TJNLIKENESS IN ORGANISMS. 161 



evidence from paleontology, from embryology, from 

 the well-hierarchized classification of the organisms, 

 demands as its indispensable complement spontane- 

 ous formation, without germs, without parents, of 

 the first examples of the living world. 



"In the scientific domain, any logical and neces- 

 sary deduction or induction ought to be admitted 

 without contest, though it may shock old ideas and 

 shatter old dogmas." (Page 301.) 



Here is much more audacity than acuteness. In 

 contradiction to Darwin, and against Tyndall, against 

 Huxley, against all the cautious men in our modern 

 physical research, this representative of Hackel's 

 school asserts spontaneous generation. He is to be 

 pitied, but needs no reply here. 



Nevertheless, when I turn to Letourneau's defini- 

 tion of life, this is the second strategic point in 

 any book on biology: feel the pulse at these two 

 places in any volume on which you cannot spend 

 more than twenty minutes, I find Herbert Spencer's 

 definition rejected in the name of late research : 



"The definition of H. Spencer, 'the continual 

 agreement between interior and exterior relations,' 

 has the fault of being too abstract, and of soaring so 

 high above facts that it ceases to recall them. Be- 

 sides, just by reason of its vague generality, it might 

 also be applied to certain continuous chemical phe- 

 nomena. 



"It would be better to descend nearer to the earth, 

 and to limit ourselves to giving a short summary of 

 the principal vital facts which have been observed. 



